Describing data is an important skill. Data visualization allows readers to get a concept of the data from a single display. To describe qualitative data we can break data down into categories called classes.
| A class is one of the categories into which qualitative data can be classified. |
| The class frequency is the number of observations in the data set that fall into a particular class. |
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The class relative frequency is the class frequency divided by the total number of observations in the data set; that is, \[class\,relatve\,frequency\,=\frac{class\,frequency}{n}\] |
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The class percentage is the class relative frequency multiplied by 100; that is, \[class\,percentage\,= (class\,relative\,frequency) \times 100\] |
With the above calculations you can display the data in a bar graph or pie chart.
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Statistics by Matthew Cheung. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.